GB1391194A - Method of and apparatus for automatically controlling the speed at which an original and copying material pass through a copying machine - Google Patents

Abstract

1391194 Photo-copying apparatus HOECHST AG 20 April 1972 [22 April 1971 31 Jan 1972 (4)] 18305/72 Heading G2A Each original fed through a copier gives rise to a speed-determining signal before the preceding original has left the exposure zone, this signal is stored until the preceding original has left the exposure zone, and then the signal is used to control the speed of a motor 21 as it feeds the original and copy material through the exposure zone. Preferably the signals are obtained by measuring the translucency of successive originals. In the embodiment shown, as originals pass through the copier they trip switches S 2 , S 3 , S 4 , S 6 , S 7 , S 14 , S 15 to initiate the various steps of the process. As each original is fed in, the translucency of different areas thereof is measured using filters 9a-9e, 9a'-9e' photo-sensitive elements 8a-8e, 8a'-8e' and amplifiers 10a-10e, 10a'-10e'; and for each original the signal corresponding to the greatest translucency is selected by discriminators 11, 11'. The following sequence takes place: a first original passes photosensitive elements 8, the resulting signal is stored by a capacitor C 2 , a second original passes photosensitive elements 8' the resulting signal is stored by capacitor C 3 , the signal on C 2 is applied to a speed controller 19 of motor 21 and the first original is copied, the signal on C 1 is discharged, the first original is ejected at maximum speed, the signal on C3 is applied to controller 19, the second original is copied, C 2 is discharged, and the second original is ejected at maximum speed. Preferably light is conducted from the copying source to measure translucency (e.g. by mirrors, metal tubes, fibre optics). Lamps (L1-L3) Fig. 4 (not shown), are used to synchronize the different parts of the circuit.